I'm not so convinced that Nucky is giving Jimmy's wife money. I think that money is actually coming from Jimmy and he is just using Nucky's address.

I think Doyle is a fifth wheel and will shortly be removed by either Nucky/Chalky or Luciano/D'Alessio Brothers.

"When the snows fall and the white winds blow, the lone wolf dies but the pack survives."
Winter is Coming

Now this is the Law of the Jungle—as old and as true as the sky; And the wolf that shall keep it may prosper, but the wolf that shall break it must die.
As the creeper that girdles the tree-trunk, the Law runneth forward and back; For the strength of the Pack is the Wolf, and the strength of the Wolf is the Pack.